Drilling apparatus and method



Feb. 22, 1966 w. D. LEAKE 3,236,308

DRILLING APPARATUS AND METHOD Filed April 4., 1960 5 Sheets-Sheet l IN VEN TOR. W/LLWM 0. 454%5 BY M/VM Feb. 22, 1966 w. D. LEAKE DRILLING APPARATUS AND METHOD 5 Sheets-Sheet 2 Filed April 4, 1960 W NW KI II I M IN VEN TOR. W/LL/FM 0. LEQZE BY WM 777'0Z/V5y Feb. 22, 1966 w. D. LEAKE DRILLING APPARATUS AND METHOD 5 Sheets-Sheet 3 Filed April 4, 1960 IN V EN TOR. MAL 7/%' 0. 1.5485 :62; Z %M Feb. 22, 1966 w. D. LEAKE DRILLING APPARATUS AND METHOD 5 Sheets-Sheet 4.

Filed. April 4, 1960 mm M VA N m0 2 M w 4 7 u p w Feb. 22, 1966 w. D. LEAKE 3,236,308

DRILLING APPARATUS AND METHOD Filed April 4. 1960 5 Sheets-Sheet 5 INVENTOR. 52 [6 69 W/LL/QM a 454/45 BYKQM//%M A77702A/EV United States Patent 3,236,308 DRILLING APPARATUS AND METHOD William D. Leake, Long Beach, Calif., assignor to Richfield Oil Corporation, Los Angeles, Calif., a corporation of Delaware Filed Apr. 4, 1960, Ser. No. 19,722 16 Claims. (Cl. 166-46) The present invention relates to a submarine drilling technique and more particularly relates to apparatus and a method for drilling a well bore into and re-entering a formation underlying a body of water from a floating vessel.

Drilling into a formation underlying a body of water such as an ocean from a drilling barge presents many operating problems due to movement of the floating drilling barge relative to the ocean floor. In the past, time lost in attempting to re-enter a well bore drilled into the ocean floor or well head equipment mounted thereon has been a substantial factor in offshore drilling costs. Damage to well head equipment and submarine control hoses by drill bits and other drilling equipment has also been excessive and costly. Recent proposals to re-enter the well head from a floating barge have been to provide guide lines extending from the floating barge to a base plate anchored at the ocean floor. Guide lines are generally satisfactory for locating equipment when an auxiliary guiding means such as a funnel can be used to direct equipment from the general area into a specific opening, however because of lateral displacement of the guide lines, particularly when heavy equipment is being lowered to the well, their use is seriously limited in applications where auxiliary guiding equipment is not feasible.

It is, therefore, an object of the present invention to provide a method and apparatus for drilling a well bore in a formation underlying a body of water from a floating barge.

It is also an object of the present invention to provide apparatus and a method for landing drilling and production equipment on the ocean floor adjacent a well bore whereby re-entry into the well bore and the equipment appurtenant thereto may be effected.

It is a further object of this invention to provide apparatus and a method for positively guiding drilling equipment into a well bore drilled in the ocean floor and into Well head apparatus positioned in the Well bore.

Other objects and a more complete understanding of my invention may be had by reference to the specification and the appended claims taken in conjunction with the drawings in which:

FIGURE 1 shows a floating drilling barge, partially in section, positioned over a submarine well bore with drilling equipment mounted thereon for the drilling oper- I ation;

FIGURE 2 shows the manner in which the Well bore is drilled preparatory to placement of a landing base thereover;

FIGURE 3 shows the apparatus used to place a conductor pipe in the well bore;

FIGURE 4 shows apparatus used for deepening the well for placement of a surface casing;

FIGURE 5 shows apparatus for landing the surface casing in the hole;

FIGURE 6 shows the manner in which the blowout prevention equipment is lowered to the ocean floor;

FIGURE 7 shows the blowout prevention equipment preparatory to landing at the ocean floor;

FIGURE 8 shows a casing riser preparatory to latching in the blowout prevention equipment;

FIGURE 9 shows the cement landing base with a sleeve extending therethrough;

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FIGURE 10 shows a section through the landing base at FIGURE 5 showing the conductor pipe and surface casing with landing mandrel, prior to releasing the surface casing from the drill string;

FIGURE 11 shows the landing base frame structure;

FIGURE 12 shows the foot which temporarily secures the landing base in the formation;

FIGURES l3 and 14 show the guide elevator used to lower a drill bit into the well;

FIGURES l5 and 16 show the guide elevator used to lower the conductor pipe into the well.

Drilling into the ocean floor from a floating drilling barge is accomplished according to my present invention by initially suspending a landing base from the barge on guide lines and drilling a hole snfliciently deep to receive the landing base. After the landing base is set on the ocean floor and the hole deepened to competent formation a conductor pipe is cemented into the hole. Where the formation below the conductor pipe is not sufiiciently competent to permit drilling with sea water when deepening the hole for the surface casing, or when cutting samples are required, a circulating system can be effected by employing an inside-outside packer to seal between the drill string and conductor pipe. In the process of setting the surface casing, provision is made for maintaining entry into the hole by the use of a stinger. This is accomplished by the use of a surface casing release tool for lowering the surface casing into the hole with the drill string, the tool being adapted to hold inside the surface casing a suificient length of drill pipe or stinger to reach from the barge to the surface casing landing mandrel when in position at the well head. After lowering the surface casing with a landing mandrel attached to the upper end thereof, to rest on the conductor pipe and cementing, the drill pipe is rotated to the right to disengage the surface casing from the drill pipe and stinger. The drill pipe is then hoisted until the casing release tool is raised to the ships well, and the releasing tool is replaced with a lowering su-b over which the blowout preventer is latched. The drill pipe stinger which extends below the lowering sub and surface casing release tool, maintains entry into the surface casing landing mandrel so that the blowout prevention equipment may then be lowered with the drill pipe and latched over the surface casing landing mandrel. The upper end of the blowout prevention equipment is then released from the lowering sub, and an appropriate flexible casing riser connected to the upper end of the blowout prevention equipment. Drilling is then conducted by lowering a bit on the drill pipe through the casing riser, well head equipment and surface casing.

Referring now more particularly to the drawings, FIG- URE 1 shows a barge 1 having mounted thereon oil well drilling equipment adapted for drilling into the ocean floor. The ships well 3 provides working access to the underwater formation. A rotary table 5 is supported on platform 7 which rests over the ships well 3 during the drilling operation. Drill string 9 is raised or lowered into the well 3 through rotary table 5 by hoisting cable 11 and traveling block 13 connected with a book 15 and swivel 17 to kelly 18. The hoisting cable 11 is supported by a crown block 19 at the top of derrick 21 and is powered by draw works 23. Kelly bushing 25 mounted in the powered rotary table 5 grips square kelly 18 to transmit rotary power to the drill string through a kelly joint (not shown).

Drilling fluid is pumped into the hollow drill string with mud pump 31 and is returned to mud shakers 35 and the mud conditioning tank through a casing riser 32 and pitcher nipple 33. The rig fioor 8 is raised above the main deck 37 and the circulating pit 30 installed below the main deck to enable mud to flow from the pitcher nipple 33 at the top of the casing riser 32 onto the mud shakers and into the circulating pit.

As shown in FIGURE 2 a heavy landing base 39 is suspended from the drilling barge on cable guide lines 41 over the formation to be drilled. A conventional rock bit 43 affixed to the lower end of drill column 9, is stabbed through a large diameter sleeve 45 provided in the landing base 39 and a large diameter hole 47 is drilled into the ocean floor 49 sufficiently deep to seat the lower projecting portion 45b of sleeve 45. Bit guide elevator 51 (shown in detail in FIGURES 13 and 14) is slidably mounted on guide lines 41 to direct bit 43 into the sleeve 45 in landing base 39. The elevator is retracted to the ship on a sand-line (not shown). The upper end 45a of the landing base sleeve is provided with a funnel 46 to aid in directing equipment into the sleeve. After drilling the initial hole 47, and with the drill string still in the hole, landing base 39 is lowered on the wire lines 41 to rest on the ocean bottom with the large diameter sleeve projecting into the hole and surface engaging feet 40 penetrate the ocean floor.

At this point preparation is made to set and cement a conductor pipe if the formation is not sufliciently competent to proceed with the setting of a surface casing. In the instances Where a conductor pipe is considered desirable, the drill string 9 is operated to deepen the hole 47 to competent formation. Drill pipe 9 is then withdrawn from the hole up to the vessel and bit 43 removed. A suitable conductor pipe 55 as shown in FIG- URE 3, is lowered with the drill string 9 using a crossover joint 57 and a suitable release tool 59 such as that shown in US. Patent No. 2,917,281, and guided into the hole through funnel 46 with a conductor pipe guide elevator 61 (shown in detail in FIGURES 15 and 16) on guide lines 41.

As best viewed in FIGURE 10, a shoulder 63 on the conductor pipe 55 near the upper end thereof rests on shoulder 64 of sleeve 45 and supports the conductor pipe in the landing base. Shoulder 64 is formed in the landing base sleeve 45 by the welding of an inner sleeve 45b to upper sleeve 45a. Since the shoulder 64 on which the conductor pipe rests is spaced well below the funnel 46, the upper end of the conductor pipe does not project above the lower end of the funnel. Elevator 61 (shown in detail in FIGURES 15 and 16) is provided with spaced-apart tubular guides 65 and a central opening 67 through which the conductor pipe extends. A pivoted spring loaded latch 69 is carried on the conductor pipe elevator so that the elevator can be raised with a sand line 71 after the elevator has served its purpose in guiding the conductor pipe into the sleeve 45. This oneway latch permits the shoulder 63 on the conductor pipe to pass through the central opening 67, of the elevator, as the elevator 61 is raised to the boat on sand line 71. The teeth 73, provided at the lower extremity of the conductor pipe, prevent the guide elevator from slipping off the lower end of the conductor pipe.

Any debris in the newly drilled conductor pipe hole may be cleaned out by rota-ting the teeth-equipped conductor pipe and pumping fluid therethrough in the conventional manner. The conductor pipe is then cemented in place and the drill pipe disconnected from the conductor pipe by actuating the releasing tool 59. This may be accomplished by dropping a ball through the interior of the drill pipe and applying fluid pressure as described in US. Patent No. 2,917,281.

The drill pipe, crossover pipe, and release tool are then withdrawn and the drill string equipped with a smaller bit 75 to deepen the hole to receive a surface casing. The hole is deepened to approximately 50 feet deeper than the length of surface casing to be set. Bit 75 is guided into funnel 46 on a bit guide elevator 51 which is subsequently raised to the barge on a sand line. If the formation is not sufliciently competent to permit drilling with sea water in the conventional manner or if sample cuttings are required for geological information, a circulating drilling system may be installed by employing an inside-outside packer 77 as shown in FIGURE 4 in the annulus between the rotating drill pipe 9 and the upper end of the stationary conductor pipe. A side outlet 79 is provided with a hose extending to the ship to conduct return fluid and cuttings to the ship. The shoulder 87 of the inside-outside packer seats against the top of the conductor pipe. Mechanical latching means are provided for securing a conventional submarine drilling head 89 to the inside-outside packer. The inside-outside packer hydraulically seals against the inside of the conductor and the submarine drilling head 89 hydraulically seals against the rotating drill pipe thus causing the return circulation flowing up through the annulus between the conductor pipe and drill pipe to flow through outlet 79 and back to the barge.

Float shoe equipped sunface casing 91 is made up in the ships well 3 and provided at the upper end thereof with a landing mandrel 93 (shown in detail in FIG- URE 10), which has the same internal diameter as the surface casing. Landing mandrel 93 is provided with external lugs 95 adapted to rest upon the top of the conductor pipe 55 to thereby support the landing mandrel within the conductor pipe, and external lugs 96 upon which the blowout prevention equipment rests. A grooved portion 97 in the landing mandrel is adapted to receive the sliding gates of a conventional gate valve 99 on the lower portion of the blowout prevention assembly 101. This gate valve latches the blowout prevention assembly to the surface casing after the casing has been set and cemented in the hole.

Drill pipe 9 is used to lower the surface easing into the sleeve 45 with the aid of a guide elevator slidably attached to guide lines 41. The drill pipe 9 is releasa bly connected to the surface casing through landing mandrel 93 by means of a releasing tool 103 (shown in detail in FIGURE 10) provided with a left-hand thread portion 105 for threadab-ly engaging the landing mandrel on the upper end of the surface casing and a conventional right-hand threaded portion 107 for engaging a drill pipe stinger 109 over which the surface casing is suspended. After the surface casing has been lowered into the hole through funnel 46, as shown in FIGURE 5, and the lugs 95 of the surface casing landing mandrel 93 come to rest on the top of the conductor pipe, cement is pumped down through the drill pipe to cement the surface casing firmly in place within the competent formation and to the previously installed conductor pipe and landing base. Cement is excluded from the stinger with conventional swabs and from the surface casing-stinger annulus by the surface casing float shoe. By rotating the drill pipe to the right, the drill pipe 9 and stinger 109 are disengaged from the surface casing landing mandrel 93 at the left-hand thread 105.

The stinger 109 or portion of the drill pipe below the releasing tool 103 is of greater length than the water depth and serves to maintain entry into the landing mandrel from the ship after the surface casing has been set and connected and the release tool 103 raised to the ship so that the lower gate valve portion 99 of the blowout prevention assembly 101 may be positively guided and latched to the surface casing. The release tool is withdrawn from the well after being released from the surface casing at 105, by withdrawing the drill string until the release tool 103 with the stinger extending therefrom is raised to the ships well 3. The lower end of the stinger 109 projects into the top of the surface casing landing mandrel 93. The releasing tool 103 is removed from the top of the stinger and is replaced between the drill pipe and stinger with a lowering sub 110 (FIGURE 6) which is threada b-ly connected to the stinger at 1-11.

The lowering sub 110 as viewed in FIGURE 6 is provided with a recessed portion for temporarily latching the top of the blowout prevention assembly 101 thereon for the purpose of lowering the blowout prevention assembly to the ocean floor. Latching pins 118 are provided in the blowout prevention assembly for engaging recessed portion 115 as above described. The blowout prevention assembly 101 is supported in the well on support arms 117 until the lowering sub 110 is connected for lowering the blowout prevention assembly onto the ocean floor. The top of the blowout prevention assembly which is conventional, is provided with a funnel 119 for guiding drill bits and other equipment therethrough.

After the upper end of the blowout preventer assembly is temporarily latched to the lowering sub, as shown in FIGURE 7, drill pipe is connected to the upper end of the lowering sub at 121 section by section, and the blowout preventer assembly 101, stinger 109, and drill string are lowered to the ocean floor. Since the stinger maintains entry into the landing mandrel 93, the blowout prevention assembly is positively guided into position and the lower end thereof attached to the surface casing landing mandrel Without the use of guide lines. The blowout preventer assembly comes to rest when the lower end of the open gate 99 registers over the recessed portion 97 of the standing mandrel 93, and the assembly housing engages the upper set of lugs 96, as shown in FIGURE 8. The gate valve 99 is then hydraulically actuated from the barge to complete the connection between the surface casing and the blowout prevention assembly. The connection may be pressure-tested at this time through a high pressure hose above the gate valve 99 and below the blowout prevention assembly. The lowering sub 110 is disconnected from the blowout preventer assembly by remotely operating the latching pins 118. The lowering sub and stinger are then withdrawn with the drill pipe to the barge, leaving the blowout prevention assembly latched in place to the surface casing.

Re-entry of the drill string through the blowout prevention equipment and into the hole to proceed with the drilling operation may be effected either with guide lines 41 or through a flexible casing riser 32, such as is shown in US. Patent No. 2,606,003, extending to the vessel and latched to the upper end of the blowout prevention assembly. In the event that guide lines are used for re-entry, a suitable pack-01f element (not shown) should be lowered through the blowout preventers for the control of the drilling fluid. The preferred embodiment is to employ a casing riser 32 lowered into and latched to the blowout prevention equipment, on guide lines 41 with a guide elevator 125. Return circulation is then controlled through a pitcher nipple 33 at the barge as heretofore described.

The guide elevators shown in FIGURES 13 through 16 are adaptations of the basic elevator design for purposes of lowering the drill string, conductor casing, and casing riser. The structures consist essentially of a center receptacle 127 to receive the casing, etc. with rigid arm members 129 extending outwardly to slidably engage the guide lines at their outer extremities. The outer extremities of the arms are provided with cylindri cal members 131 for slidably engaging the guide lines. Cylindrical member 131 has a door member 133 provided with hinges 135 and locking members 137 to facilitate opening the cylindrical members for mounting and dismounting the guide elevator on the guide lines. The center receptacle 127 is also provided with a hinged door section 139. The conductor pipe elevator 61 is also provided with a hinged door section 141 and with a spring loaded one way latch 69 as heretofore described. Loops 143 are positioned on arms 1-29 to hitch sand lines for raising the elevator to the ship. A reinforcing web 147 may be utilized as shown in FIGURES 15 and 16.

Landing base 39 is shown in FIGURE 9 in perspective showing a frame 149 onto which television guide lines 151 anchor with books 153. The frame 149 is rotatable about pin 155 which connects the television frame to the landing base 39 through reinforcing members 157 embedded in concrete landing base. The television guide lines extend from the ship to the frame so that a television camera (not shown) may be lowered thereon. These guide lines are tensioned at the ship by hanging counterweights (not shown) over pulleys. The tension in the television guide lines not only prevents undue lateral movement of the camera, but holds the frame in a horizontal position. Through the use of the television camera the blowout prevention equipment can be visually checked at the barge, for pressure leaks or other difliculties. Frame 149 may be rotated to a vertical position 159 to facilitate lowering through the ships well 3. The concrete portion is cast about the centrally located sleeve to firmly secure the sleeve. After the concrete has hardened a lower sleeve and a funnel are welded to the upper sleeve. The welded T joint between the top of the lower sleeve 45b and the upper sleeve 45a serves as the stop 64 on which the conductor pipe shoulder 63 rests. The upper end of sleeve 45a may be ported as at 161 to provide an eXit for cement when the surface casing is being cemented.

Although I have described my invention with a certain degree of particularity, my invention is not limited to the details set forth but should be given the full scope of the appended claims.

I claim:

1. Apparatus for drilling and re-entering the well bore in a formation underlying a body of water from a drilling barge and guiding a blowout preventer from said barge to said formation comprising: in combination, an apertured landing base, guide means extending to said base from said barge for guiding drilling equipment from said barge to said well bore, a drill pipe having a drill bit thereon, means for operating said drill pipe, a surface casing having a landing mandrel connected to the upper end thereof said mandrel having a recess for latching said blowout preventer thereon, means cooperating with said guide means for guiding said easing into said landing base aperture, said blowout preventer having an upper and a lower latching means, disconnectable means connected to said surface casing, for lowering said surface casing into said well bore, extending means connected to said releasable means extending into said surface casing when said releasing means are raised to said barge, a lowering sub connectable between said extending means and said drill pipe and having a recessed portion onto which said upper blowout preventer latching means may be latched for lowering said blowout preventer onto said surface casing landing mandrel.

2. Apparatus for drilling a well bore in a formation underlying a body of water from a drilling barge and guiding a blowout preventer from said barge to said formation comprising, in combination:

an apertured landing base,

guide means extending to said base from said barge for guiding said drilling equipment from said barge to said well bore,

a drill pipe having a drill bit thereon,

means for rotating said drill pipe,

a conductor pipe,

means co-operating with said guide means for guiding said conductor pipe into said landing base aperture,

a surface casing having a landing mandrel connected to the upper end thereof,

said mandrel having shoulder means to which said blowout preventer may be latched,

co-operating means on said mandrel and said conductor pipe for supporting said surface casing in said conductor pipe,

disconnectible means connected to said surface casing for lowering said surface casing into said conductor p p extending means connected to said disconnectible means extending into said surface casing when said disconnectible means are raised to said barge, and

a lowering sub connectible between said extending means and said drill pipe and having a shouldered portion over which said blowout preventer may be latched for lowering onto said surface casing landing mandrel.

3. The apparatus of claim 2 including means in said landing base aperture for supporting said conductor pipe therein.

4. Apparatus for drilling and re-entering a well bore in a formation underlying a body of water from a drilling barge and guiding a blowout preventer from said barge to said formation, comprising in combination:

an apertured landing base,

guide means extending to said base from said barge for guiding drilling equipment from said barge to said well bore,

a drill pipe having a drill bit thereon,

means for rotating said drill pipe,

a conductor pipe having cutting means at its lower extremity,

means co-operating with said guide means for guiding said conductor pipe into the landing base aperture,

a surface casing having a landing mandrel connected to the upper end thereof,

said mandrel having shoulder means to which said blowout preventer may be latched,

co-operating means on said mandrel and said conductor pipe for supporting said surface casing in said conductor pipe,

:1 stinger,

disconnectible means connected to said surface casing for lowering said surface casing into said conductor P p a lowering sub connectible between said. stinger and said drill pipe having a shouldered portion over which said blowout preventer may be latched for lowering onto said surface casing landing mandrel.

5. Apparatus for drilling and re-entering a well bore in a formation underlying a body of water from a drilling barge and guiding a blowout preventer from said barge to said formation comprising, in combination:

an apertured landing base,

guide means extending to said base from said barge for guiding drilling equipment from said barge to said well bore,

a drill pipe having a drill bit thereon,

means on said drilling barge for rotating said drill pipe,

a surface casing having a landing mandrel connected to the upper end thereof,

said mandrel having shoulder means to which said blowout preventer may be latched,

co-operating means on said mandrel and said conductor pipe for supporting said surface casing in said conductor pipe,

means co-operating with said guide means for guiding said surface easing into said landing base aperture,

said blowout preventer having upper and lower latching means,

a surface casing release tool insertable between an upper and a lower drill pipe section of said drill pipe and adapted to releasably suspend said surface casing exteriorly of said lower drill pipe section,

a lowering sub connectible between said upper and lower drill pipe sections and having a shouldered portion .over which said upper blowout preventer latching means may be latched for lowering said blowout preventer over said lower drill pipe section onto the surface casing landing mandrel whereby said lower blowout preventer latching means are positioned adjacent said mandrel shoulder means.

6. Apparatus for drilling and re-entering the well bore in a formation underlying a body of water from a drilling barge and guiding the blowout preventer from said barge to said formation comprising, in combination:

an apertured landing base,

a drill pipe having a drill bit thereon,

means for rotating said drill pipe,

guide means extending to said base from said barge for guiding drilling equipment from said barge to said well bore,

a surface casing having a landing mandrel connected to the upper end thereof,

said mandrel having a shoulder portion for latching said blowout preventer thereon,

said blowout preventer having an upper and a lower latching means,

means cooperating with said guide means for guiding said casing into said landing base aperture,

a stinger,

disconnectible means connecting said stinger and said surface casing to said drill pipe for lowering said surface casing into said well bore,

a lowering sub connectible between said drill pipe and said stinger and having a shoulder portion over which said upper blowout preventer latching means may be latched for lowering said blowout preventer over said stinger onto the surface casing landing mandrel whereby said lower blowout preventer latching means may be latched to said mandrel shoulder means,

said stinger being so arranged and constructed to maintain contact with the well bore when said disconnectible means are disconnected and said drill pipe raised to said barge for connecting said lowering sub thereto.

7. An apparatus for drilling and re-entering a well bore in a formation underlying a body of water from a drilling barge and guiding a blowout preventer from said barge to said formation comprising, in combination:

an apertured landing base,

guide means extending to said base from said barge for guiding drilling equipment from said barge to said well bore,

a drill pipe having a drill bit thereon,

means for rotating said drill pipe from said drilling barge,

a conductor pipe,

means cooperating with said guide means for guiding said conductor pipe into said landing base aperture,

a surface casing having a landing mandrel connected to the upper end thereof,

said mandrel having shoulder means to which said blowout preventer may be latched,

said blowout preventer having an upper and lower latching means,

cooperating means on said mandrel and said conductor pipe for supporting said surface casing in said conductor pipe,

means cooperating with said guide means for guiding said casing into said landing base aperture,

a surface casing release tool insertible between two successive drill pipe sections in said drill pipe and adapted to releasably suspend said surface casing exteriorly of the lower drill pipe section,

a lowering sub connectible between said upper and lower drill pipe sections having a shouldered portion on which said upper blowout preventer latching means may be latched for lowering said blowout preventer onto said surface casing landing mandrel whereby said lower blowout preventer latching means may be latched to said mandrel shoulder means,

said lower drill pipe section being arranged and constructed to maintain contact with the well bore when said disconnectible means are disconnected and said drill pipe raised to said. barge for connecting said lowering sub thereto.

8. An apparatus for drilling and re-entering a well bore in a formation underlying a body of water from a drilling barge and guiding a blowout preventer from said barge to said formation, comprising in combination:

an apertured landing base,

a drill pipe having a drill bit thereon,

means for rotating said drill pipe,

aconductor pipe,

guide means extending to said base from said barge for guiding drilling equipment from said barge to said well bore,

means cooperating with said guide means for guiding said conductor pipe into said apertnred landing base,

a surface casing having a landing mandrel connected to the upper end thereof,

said mandrel having a shoulder means to which said blowout preventer may be latched,

said blowout preventer having an upper and lower latching means,

cooperating means on said landing mandrel and said conducting pipe for supporting said surface casing in said conductor pipe,

a stinger,

a surface casing release tool connecting said drill pipe,

said stinger and said surface casing,

said tool being adapted to releasably suspend said surface casing exteriorly above of said stinger,

a lowering sub connectible between said stinger and said drill pipe and having a shoulder portion onto which said upper blowout preventer latching means may be latched for lowering said blowout preventer onto said surface casing landing mandrel,

said stinger being so arranged and constructed to maintain contact with the well bore when said disconnectible means are disconnected and said drill pipe raised to said barge for connecting said lowering sub thereto.

9. In an apparatus for drilling and re-entering a well bore in a formation underlying a body of water wherein a floating drilling barge and a landing base positioned at the formation are inter-connected with guide lines for guiding drilling and production equipment to said formation, and wherein a conductor pipe is releasably attachable to a drill string for lowering into said well bore with guiding means slidably attached to said guide lines, and wherein a surface casing and a blowout preventer are provided, the improvement comprising,

a drill pipe stinger releasably connected to said drill string and said surface casing,

said stinger being in alignment with said drill string and being arranged to extend downwardly therefrom,

said stinger extending between said barge and said well bore,

means for disconnecting said surface casing from said stinger,

and means for guiding said blowout preventer to said formation with said stinger.

10. The apparatus of claim 9 wherein said blowout preventer has upper latching means for latching onto said blowout preventer guiding means and lower latch means for latching onto said surface casing.

11. In a submarine drilling and landing base assembly adapted for use with a camera and having camera guide lines associated therewith, and wherein an apertured concrete slab is provided with a central pipe extending therethrough, the improvement comprising:

a horizontally disposed camera guide line support frame,

means embedded in said slab for supporting said frame on said base, and

means for pivoting said frame about said base to a vertical position.

12. A method for drilling a well bore in the ocean floor from a drilling vessel through an apertured landing base on the ocean floor, comprising the steps:

inserting a lowering sub between said stinger and said drill pipe,

latching the upper portion of said blowout preventer to said lowering sub,

guiding said blowout preventer to said base on the ocean floor with said stinger,

re-entering said landing base aperture through said blowout preventer with a drill bit by lowering said drill pipe from said vessel to said floor,

and rotating said drill pipe to thereby effect the further drilling of said well bore.

13. A method for drilling a well bore in the ocean floor from a drilling vessel connected to an apertured landing base on the ocean floor by a guide line, comprising the steps:

guiding a conductor pipe through said landing base and into said well bore with said guide line,

connecting a stinger and a surface casing to a surface casing release tool,

guiding said connected stinger and surface casing from said vessel into said conductor pipe through said landing base aperture with said guide line and a drill pipe connected to said casing release tool,

inserting a lowering sub between said stinger and said drill pipe, latching the upper end of a blowout preventer to said lowering sub,

guiding said blowout preventer with said stinger to said base on the ocean floor,

re-entering said landing base aperture through said blowout preventer with a drill bit by lowering said drill pipe from said vessel to said floor,

and rotating said drill pipe to effect the further drilling of said well bore.

14. A method for drilling a well bore in the ocean floor from a drilling vessel, comprising the steps:

suspending from the drilling vessel an apertured landing base,

drilling an initial hole into the ocean floor,

lowering said base to the ocean floor,

deepening said hole for the placement of said surface casing,

suspending a surface casing from said vessel,

lowering a drill pipe stinger through said surface casing,

connecting said stinger and said surface casing to a surface casing release tool,

guiding said connected surface casing and stinger into said well bore through said base aperture with a drill pipe connected to said tool,

releasing said surface casing from said tool when said casing is landed in said base,

raising said release tool with said casing released therefrom to the barge with said stinger extending between said barge and said landed casing,

inserting a lowering sub between said stinger and said drill pipe,

latching the upper portion of a blowout preventer to said lowering sub,

guiding said blowout preventer to said base on the ocean floor with said stinger,

1 l. and re-entering said base aperture through said blowout preventer with a drill bit by lowering said drill pipe from said vessel to said floor.

15. A method for drilling a well bore in the ocean floor from a drilling vessel connected to a landing base on the ocean floor by guide lines, comprising the steps:

suspending from said vessel a landing base,

drilling an initial hole in the ocean floor With a drill pipe lowered through said base,

lowering said base to the ocean floor,

guiding a conductor pipe releasably connected to said drill pipe into said well bore through said base aperture with an elevator member slidably attached to said guide lines,

cementing said conductor pipe to said well bore,

releasing said drill pipe from said conductor pipe,

re-entering said conductor pipe with a drill bit mounted on said drill pipe by guiding said drill pipe to said floor from said vessel,

deepening said well bore for placement of a surface casing,

suspending a surface casing from said vessel,

lowering a drill pipe stinger through said surface casconnecting the upper extremities of said surface casing and said stinger to a surface casing release tool,

guiding said connected surface casing and stinger from said vessel into said conductor pipe through said base aperture with said drill pipe,

inserting a lowering sub between said stinger and said drill pipe,

latching the upper portion of a blowout preventer to said lowering sub,

lowering said blowout preventer to the ocean floor,

and re-entering said base aperture through said blowout preventer with a drill bit by lowering said d-rill pipe from said vessel to said floor.

16. The method of claim 15 including the steps of latching a casing riser to said blowout preventer and lowering said drill bit through said casing riser and said blowout preventer to resume drilling operations.

References Cited by the Examiner UNITED STATES PATENTS CHARLES E. OCONNELL, Primary Examiner.

R. E. FAVREAU, Assistant Examiner. 

13. A METHOD FOR DRILLING A WELL BORE IN THE OCEAN FLOOR FROM A DRILLING VESSEL CONNECTED TO AN APERTURED LANDING BASE ON THE OCEAN FLOOR BY A GUIDE LINE, COMPRISING THE STEPS; GUIDING A CONDUCTOR PIPE THROUGH SAID LANDING BASE AND INTO SAID WELL BORE WITH SAID GUIDE LINE, CONNECTING A STINGER AND A SURFACE CASING TO A SURFACE CASING RELEASE TOOL, GUIDING SAID CONNECTED STINGER AND SURFACE CASING FROM SAID VESSEL INTO SAID CONDUCTOR PIPE THROUGH SAID LANDING BASE APERTURE WITH SAID GUIDE LINE AND A DRILL PIPE CONNECTED TO SAID CASING RELEASE TOOL, INSERTING A LOWERING SUB BETWEEN SAID STRINGER AND SAID DRILL PIPE, LATCHING THE UPPER END OF A BLOWOUT PREVENTER TO SAID LOWERING SUB, GUIDING SAID BLOWOUT PREVENTER WITH SAID STINGER TO SAID BASE ON THE OCEAN FLOOR, RE-ENTERING SAID LANDING BASE APERTURE THROUGH SAID 